Quadruplex telegraphy



Nb Mode-1.)

O. D. HASKI'N'S. QUADRUPLEX TELEGRAPHY.

Patented Ju1y '7, 1891.

[UNITED STATES PATENT OFFICE;

CHARLES D. HASKINS,"OF BROOKLYN, NEW YORK, A'ssIcNoR To THE WESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS.

QUADRUPLEX TELEGRAPHY.

SPECIFICATION forming part of Letters iPatent No. 455,398, dated July 7, 1891.

Application filed November 19, 1887. Serial No. 255,601,

To all whom, it mag concern:

' Be it known that I, CHARLES DARWIN'HAs mm, a citizen of the United States, residing at Brooklyn, in the countyof Kings and State of New York, have invented a certain new and useful Improvement in Quadruplex Telegraphy, of which the following is a full, clear,

concise,-and exact description, reference being had to the accompanying drawings, form ing a part of this Specification.

In quadruplex systems of telegraphy one line is provided at each end with two receiving and two transmitting instruments, with circuits so arranged that four messages may.

be simultaneously transmitted over the single 11nethatis.to say, four operators are required at each end of the line, two for sending and two for receiving. Considering the apparatus at one end of the line we have two receiving-instruments, one a polarized relay and the other a neutral relay. 'The transmittihg-instrw' ments consist one of a double-current transmitter or pole-changer and the other of a single-current transmitter or continuity circuitpreserving key. The receiving-instruments are wound difierentially in the well-known way, so that the current sent through their coils by the transmitting-instruments at the same end of the line will not operate either of them. This is accomplished in brief by sending current in branches through the difcaused at the neutral relay when the polarity of its current is changed by the double-current transmitter at the distant end during the time that the armature of said.ne utral relay should be held up by the operation of the Sim gle-current transmitter.

My invention is designed to avoid such false signals; and it consists inan extra helix on contact-points of both relays being connected (No model.)

I consecutively .in the local circuit with'the sounder and local battery, thus making it necessary that both armature-levers should rest against the back contact-points to close the circuitthat is to say, when either relay is energized the local circuit 'is held open. By this means when the neutral relay gives a false signal by the falling away or kicking of its armature an induced current is generated in the extra coil, and this induced current passing through the coils'of the ordinary relay energizes the same and its armature is attracted momentarily, and thus the circuit is opened at said ordinary relay local contactpoints at the time the circuit is falsely closed at theneutral relay; by the kick of its armature. with the local contacts of both relays, it will not be actuated by the kick or false signals The sounder being in the same circuit of the neutral relay, since the induced current sent, as before described, through the coils of the ordinary relay will cause said relay to hold the circuit through the sounder open during the'time that the armature of the neutralrelay is away from its poles.

My invention isill-ustrated in theaccompanying drawings, in which-- Figure 1 is a View of the neutral relay with its attendant relay and sounder at one end of the line. of my method of winding adifferential relay.

Like parts are indicated by similar letters of reference throughout both figures.

Fig. 2 is a diagram illustrative The magnet of the neutral relay, in addition to the differential or working coils, is provided with an extra coil a. This coil a is includedin the circuit of the coils of the relay b. If now while the magnet of the neu-- tral relay is energized its polarity be suddenly reversed, its armature cwould drop back mo mentarily or kick, so as toclose the circuit at d; but at -the same time acurrent would be momentarily induced in the extra coil a and this induced current sent through the coils of relay 1) energizes the same,.thus moving the armature-lever e to open the circuit at f.

Thus when the circuit is closed atd by the I kicking of the armature the circuit will be broken at f, and hence no false signal will be given by the sounder. the neutral relay is-demagnetized by dimin- WVhen the magnet of.

ishing the strength of the current, as is done in case of true signals, the armatures 6 will remain back, soas to close the circuit at f during the time the armature c closes the circuit at d. Thus the local circuit is opened and closed at the will of the operator who is working the single transmitter at the distant end, and no false signals can be transmitted.

The method I have illustrated in the drawings I consider the best manner of carrying out my invention.

Any manner of connecting the armature e, which is operated by the extra current, with the circuit of the local sounder, so as to pre- Vent magnetizing said local sounder at the time the extra currentis generated, I consider within my invention.

The method of differential winding illustrated in Fig. 2 forms the subject-matter of another application filed of even date herewith.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. Thelocal circuit of a neutral quad rnpleX relay, in combination with the contact-points d of said relay, a battery, a signaling device, and the contact-points of the relay 5, the electro-magnet of said relay being included in circuit, with a third winding or helix upon the magnets of the quadruplex neutral relay, whereby the local circuit through the signaling device is closed when the armature-levers of both relays are simultaneously on their back contacts,

2, A local circuit containing a battery, a sounder, and the contacts of two relays, one of said relays being a quadruplex neutral relay and the other being a relay with its coils included in circuit with a special helix or third winding upon the electro'magnet of the quadruplex neutral relay, whereby the local circuit through the sounder is closed when the armature-levers of both relays are simultaneously on their back contacts.

In witness whereof I hereunto subscribe my name this 5th day of October, A. D. 1887.

CHARLES D. HASKINS. [n 8.]

Witnesses:

JOHN J. OARTY, MILLSH. LANDON. 

